Merge branch 'bpf-misc-selftest-improvements'

Joe Stringer says:

====================
This is series makes some minor changes primarily focused on making it easier
to understand why test_verifier is failing a test. This includes printing the
observed output when a test fails in a different way than expected, or when
unprivileged tests fail due to sysctl kernel.unprivileged_bpf_disabled=1. The
last patch removes some apparently dead code.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

2 files changed, 34 insertions, 9 deletions

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5fb69a85d967..3c74b163eaeb 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -508,10 +508,6 @@ err:
 static const int caller_saved[CALLER_SAVED_REGS] = {
         BPF_REG_0, BPF_REG_1, BPF_REG_2, BPF_REG_3, BPF_REG_4, BPF_REG_5
 };
-#define CALLEE_SAVED_REGS 5
-static const int callee_saved[CALLEE_SAVED_REGS] = {
-        BPF_REG_6, BPF_REG_7, BPF_REG_8, BPF_REG_9
-};
 
 static void __mark_reg_not_init(struct bpf_reg_state *reg);
 
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index c0f16e93f9bd..2971ba2829ac 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -57,6 +57,9 @@
 #define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS      (1 << 0)
 #define F_LOAD_WITH_STRICT_ALIGNMENT            (1 << 1)
 
+#define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled"
+static bool unpriv_disabled = false;
+
 struct bpf_test {
         const char *descr;
         struct bpf_insn insns[MAX_INSNS];
@@ -11291,7 +11294,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
                         goto fail_log;
                 }
                 if (!strstr(bpf_vlog, expected_err) && !reject_from_alignment) {
-                        printf("FAIL\nUnexpected error message!\n");
+                        printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n",
+                              expected_err, bpf_vlog);
                         goto fail_log;
                 }
         }
@@ -11375,9 +11379,20 @@ out:
         return ret;
 }
 
+static void get_unpriv_disabled()
+{
+        char buf[2];
+        FILE *fd;
+
+        fd = fopen("/proc/sys/"UNPRIV_SYSCTL, "r");
+        if (fgets(buf, 2, fd) == buf && atoi(buf))
+                unpriv_disabled = true;
+        fclose(fd);
+}
+
 static int do_test(bool unpriv, unsigned int from, unsigned int to)
 {
-        int i, passes = 0, errors = 0;
+        int i, passes = 0, errors = 0, skips = 0;
 
         for (i = from; i < to; i++) {
                 struct bpf_test *test = &tests[i];
@@ -11385,7 +11400,10 @@ static int do_test(bool unpriv, unsigned int from, unsigned int to)
                 /* Program types that are not supported by non-root we
                  * skip right away.
                  */
-                if (!test->prog_type) {
+                if (!test->prog_type && unpriv_disabled) {
+                        printf("#%d/u %s SKIP\n", i, test->descr);
+                        skips++;
+                } else if (!test->prog_type) {
                         if (!unpriv)
                                 set_admin(false);
                         printf("#%d/u %s ", i, test->descr);
@@ -11394,13 +11412,17 @@ static int do_test(bool unpriv, unsigned int from, unsigned int to)
                                 set_admin(true);
                 }
 
-                if (!unpriv) {
+                if (unpriv) {
+                        printf("#%d/p %s SKIP\n", i, test->descr);
+                        skips++;
+                } else {
                         printf("#%d/p %s ", i, test->descr);
                         do_test_single(test, false, &passes, &errors);
                 }
         }
 
-        printf("Summary: %d PASSED, %d FAILED\n", passes, errors);
+        printf("Summary: %d PASSED, %d SKIPPED, %d FAILED\n", passes,
+               skips, errors);
         return errors ? EXIT_FAILURE : EXIT_SUCCESS;
 }
 
@@ -11428,6 +11450,13 @@ int main(int argc, char **argv)
                 }
         }
 
+        get_unpriv_disabled();
+        if (unpriv && unpriv_disabled) {
+                printf("Cannot run as unprivileged user with sysctl %s.\n",
+                       UNPRIV_SYSCTL);
+                return EXIT_FAILURE;
+        }
+
         setrlimit(RLIMIT_MEMLOCK, unpriv ? &rlim : &rinf);
         return do_test(unpriv, from, to);
 }